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catapultam_habeo

btrfs incremental snapshots

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Hi, this is mostly a WIP thread, but as of the first post it does work up to my relatively limited testing. I plan on expanding this to a fully featured plugin, but this script is a working foundation, and I'd like to make this available to people to play with asap.

Bottom Line Up Front: This script only works on your btrfs-formatted array drives. By default, it will keep 8760 snapshots (1 year of hourly snapshots), this value can be adjusted by changing the MAX_SNAPS variable in the script. This script does not handle cache drives, but would be trivial to extend to do so - I just think it is a bad idea. Detection of this is minimal but present. Running this script for the first time will remove and recreate all of your existing array shares (moved to temporary path, original path converted to subvolume, moved back), no data should be lost, but I have only tested this with my own data and configuration, and cannot account for all edge cases and I absolutely cannot be held accountable for your data if it is lostNo script is provided to revert these changes.

 

Goals: I wanted to have delta snapshot recovery as part of my NAS feature set. FreeNAS is appealing, but I dislike FreeBSD's ecosystem (weird problems with bhyve, don't really need ZFS performance improvements), tried ProxMox and didn't care for it, didn't want to roll my own (likely debian-based) setup, very much like unRAID's GUI and asynchronous drive upgrade process, and wasn't interested in the crazy ZFS-on-unRAID frankenstein config by Wendell at L1T. I noted that unRAID can be configured to use BTRFS, and in theory it should be able to do this, given enough scripting to keep everything in sync. I also want to leverage unRAID's GUI as heavily as possible, and do as little command-line work on the regular as possible. Adding a new drive, creating a new share, etc, should all be possible through the GUI, and this setup should automagically adjust.


Step 1) Adjust your Settings -> SMB -> SMB Extras field to include the following line. This will publish your snapshots to windows SMB clients as 'previous versions'.

vfs objects = shadow_copy2

Notes: This config does work at the global scope (where adding it to extras puts it by default), and will apply to all of your shares. You just don't get to configure any of the other options for this feature. Unfortunately, duplicating the UnRAID team's work to build share configs on the fly is outside of my ambition, so I'm willing to live with that compromise. This is going to get us into an interesting situation, where the only place samba seems to be able to find our snapshots directory is at '/mnt/user/.snapshots'. The directory needs to be created on each storage device and then let unraid aggregate it later, so we are going to do it in the script so we can handle new drives and new shares correctly.

Step 2) Install the CA Userscripts Plugin. Details of this step are outside the scope of this post.

 

Step 3) Settings -> User Scripts. Add New Script. Click on script name to edit it. Add the following code to the script. Adjust MAX_SNAPS to your preference. Schedule it as you desire. Adjust EXCLUDE to your preference.

Random Notes: This provides some, but minimal protection from ransomware and bit-rot. In particular, ransomware which understands a linux system and actually gets access to the server could purge snapshots.

Edit 1/6/20: Added options to exclude some shares from being snapshotted. -e\--exclude <Comma seperated list of shortnames>

#!/bin/bash
#description=This script implements incremental snapshots on btrfs array drives.
#arrayStarted=true
#argumentDescription= -n|--number <MAXIMUM NUMBER OF SNAPSHOTS TO RETAIL>
#argumentDefault=-s 8760

shopt -s nullglob #make empty directories not freak out
date=$(TZ=GMT date +@GMT-%Y.%m.%d-%H.%M.%S) #standardized datestamp
MAX_SNAPS=8760
EXCLUDE=

is_btrfs_subvolume() {
    local dir=$1
    [ "$(stat -f --format="%T" "$dir")" == "btrfs" ] || return 1
    inode="$(stat --format="%i" "$dir")"
    case "$inode" in
        2|256)
            return 0;;
        *)
            return 1;;
    esac
}

POSITIONAL=()
while [[ $# -gt 0 ]]
do
key="$1"

case $key in
    -n|--number)
    MAX_SNAPS="$2"
    shift # past argument
    shift # past value
    ;;
    -e|--exclude)
    EXCLUDE="$2"
    shift # past argument
    shift # past value
    ;;
    *)
    POSITIONAL+=("$1") # save it in an array for later
    shift # past argument
    ;;
esac
done
set -- "${POSITIONAL[@]}" # restore positional parameters

#ADJUST MAX_SNAPS to prevent off-by-1
MAX_SNAPS=$((MAX_SNAPS+1))

#Tokenize exclude list
declare -A excludes
for token in ${EXCLUDE//,/ }; do
	excludes[$token]=1
done

#iterate over all disks on array
for disk in /mnt/disk*[0-9]* ; do
#examine disk for btrfs-formatting (MOSTLY UNTESTED)
 if is_btrfs_subvolume $disk ; then 
  #check for .snapshots directory prior to generating snapshot
  if [ -d "$disk" ]; then
   if [ ! -d "$disk/.snapshots/" ] ; then
    mkdir -v $disk/.snapshots
   fi
   if [ ! -d "$disk/.snapshots/$date/" ] ; then
    mkdir -v $disk/.snapshots/$date
   fi
  fi
 #iterate over shares present on disk
  for share in ${disk}/* ; do
   #test for exclusion
   if [ ! -n "${excludes[$(basename $share)]}" ]; then
    #echo "Examining $share on $disk"
    is_btrfs_subvolume $share
    if [ ! "$?" -eq 0 ]; then
     #echo "$share is likely not a subvolume"
     mv -v ${share} ${share}_TEMP
     btrfs subvolume create $share
     cp -avT --reflink=always ${share}_TEMP $share
     rm -vrf ${share}_TEMP
    fi
    #make new snap
    btrfs subvolume snap -r ${share} /mnt/$(basename $disk)/.snapshots/${date}/$(basename $share)
   else
    echo "$share is on the exclusion list. Skipping..."
   fi
  done
  #find old snaps
  echo "Found $(find ${disk}/.snapshots/ -maxdepth 1 -mindepth 1 | sort -nr | tail -n +$MAX_SNAPS | wc -l) old snaps"
  for snap in $(find ${disk}/.snapshots/ -maxdepth 1 -mindepth 1 | sort -nr | tail -n +$MAX_SNAPS); do
   for share_snap in ${snap}/*; do
    btrfs subvolume delete $share_snap
   done
   rm -rfv $snap
  done
 fi
done

 

Edited by catapultam_habeo
updated script

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Posted (edited)

Here is a housekeeping script. By default just deletes empty timestamp directories. Optionally, it can delete snapshots.

 

-a purges all snapshots

-i <Comma seperated list of shares> purges the selected shares. example -i Downloads,Test1,Test2 will purge all snapshots for Downloads, Test1, and Test2.

 

#!/bin/bash
shopt -s nullglob

POSITIONAL=()
while [[ $# -gt 0 ]]
do
key="$1"

case $key in
    -i|--include)
    INCLUDE="$2"
    shift # past argument
    shift # past value
    ;;
    -a|--all)
    ALL=YES
    shift
    ;;
    *)    # unknown option
    POSITIONAL+=("$1") # save it in an array for later
    shift # past argument
    ;;
esac
done
set -- "${POSITIONAL[@]}" # restore positional parameters

#Tokenize include list
declare -A includes
for token in ${INCLUDE//,/ }; do
        includes[$token]=1
done

#iterate over all disks on array
for disk in /mnt/disk*[0-9]* ; do
 #iterate over each timestamp
 for timestamp in ${disk}/.snapshots/* ; do
  #iterate over each share in the timestamp
  for snap in $timestamp/* ; do
   if [ -n "${includes[$(basename $snap)]}" ] || [ "$ALL" = "YES" ] ; then
    echo "Purging - $snap"
    btrfs subvolume delete $snap
  fi
  #check for empty timestamp
  if [ ! "$(ls -A $timestamp)" ] ; then
   echo "Purging empty directory - $timestamp"
   rmdir $timestamp
  fi
  done
 done
done

 

Edited by catapultam_habeo

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Hello, Thank you for your great job.

For snapshot disks, it works.

I can see a list by command "btrfs sub list /mnt/diskN", but it doesn't work via windows 10 access to check the previous version.

Does it conflict with "Enhanced macOS interoperability" option? If it is, may I just restore the disks to some specific time point?

And what do we do with the cache drive? Seems there're no snapshot on it.

Sry, I'm not very good at linux, and do need snapshot function for data safety.

Thank you so much.

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Posted (edited)

I have most of this script working but I don't think the arguments are, it looks like the arguments are being treated as a single argument and not as individual arguments. If I echo $#, regardless of how many space separated values I put in it always comes out as 1.

 

User Scripts plugin is version 2020.03.19

Edited by Supermillhouse

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On 3/18/2020 at 5:35 AM, afon said:

Hello, Thank you for your great job.

For snapshot disks, it works.

I can see a list by command "btrfs sub list /mnt/diskN", but it doesn't work via windows 10 access to check the previous version.

Does it conflict with "Enhanced macOS interoperability" option? If it is, may I just restore the disks to some specific time point?

And what do we do with the cache drive? Seems there're no snapshot on it.

Sry, I'm not very good at linux, and do need snapshot function for data safety.

Thank you so much.


You probably didn't do Step 1 in the original post.

 

 

On 4/16/2020 at 9:36 AM, Supermillhouse said:

I have most of this script working but I don't think the arguments are, it looks like the arguments are being treated as a single argument and not as individual arguments. If I echo $#, regardless of how many space separated values I put in it always comes out as 1.

 

User Scripts plugin is version 2020.03.19

I'll check on this. It seems to be working on my local version, but admittedly I don't parse the args, I just set them in the EXCLUDE var directly.

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Hi, I did.

I paste the SMB configure field here:

Quote

#unassigned_devices_start
#Unassigned devices share includes
   include = /tmp/unassigned.devices/smb-settings.conf
#unassigned_devices_end

#vfs_recycle_start
#Recycle bin configuration
[global]
   syslog only = Yes
   log level = 0 vfs:0

#vfs_recycle_end
#shadow_copy_enable
vfs objects = shadow_copy2
#shadow_copy_end

 

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Posted (edited)

I am shocked this has not gotten more attention.

 

Lack of snapshots has been one of the only shortcomings to using unraid I have noticed. This includes VM snapshots, I already miss those in a big way to the point I think I am going to setup a VM for esxi to use vmware for VM's that don't need passthrough. It is a sad day when windows has a feature and linux doesn't lol.

 

btrfs seems to be stable as long as not used in raid 56, so I am seriously considering going with Bbtrfs for my array IF snapshots can be made to work.

 

Maybe setting it up for cache snapshots would get it more attention since most users are still on xfs arrays?

 

A few questions:

 

1: I read online that at some point in the past excessive snapshots could make btrfs slow down / have performance issues, do you know if this has been fixed?

 

2: I do not need hourly snapshots, daily / weekly would be more then enough. Is there a simple way to change the frequency?

 

3: It would be really cool if the housekeeping script could not only purge certain shares snapshots but also prune from hourly down to daily when older then X time. And from daily to weekly snapshots when older then Y time and weekly to monthly after Z time etc.

 

For example hourly for a week, then daily for a month and weekly for 3 months and monthly for a year would be a good starting point IMHO.

 

 

I would LOVE to see a plugin for this with a simple GUI.

Edited by TexasUnraid

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Been getting closer to putting my server into service and was setting up this snapshot script when I noticed it did not support folders with spaces in them.

 

After some trial and error I got it working on folders with spaces, although the exclude option still doesn't work with spaces and I can't figure out how to get it working.

 

The argument option of user scripts also seems to only support a single argument passed to the script and does not support spaces either.

 

Here is the updated script with all the $share variables wrapped in quotes and timezone changed to CST:

 

#!/bin/bash
#description=This script implements incremental snapshots on btrfs array drives.
#arrayStarted=true
#argumentDescription= -n|--number <MAXIMUM NUMBER OF SNAPSHOTS TO RETAIL>
#argumentDefault=-s 3

shopt -s nullglob #make empty directories not freak out
date=$(TZ=America/Chicago date +@CST-%Y.%m.%d-%H.%M.%S) #standardized datestamp
MAX_SNAPS=3
EXCLUDE=

is_btrfs_subvolume() {
    local dir=$1
    [ "$(stat -f --format="%T" "$dir")" == "btrfs" ] || return 1
    inode="$(stat --format="%i" "$dir")"
    case "$inode" in
        2|256)
            return 0;;
        *)
            return 1;;
    esac
}

POSITIONAL=()
while [[ $# -gt 0 ]]
do
key="$1"

case $key in
    -n|--number)
    MAX_SNAPS="$2"
    shift # past argument
    shift # past value
    ;;
    -e|--exclude)
    EXCLUDE="$2"
    shift # past argument
    shift # past value
    ;;
    *)
    POSITIONAL+=("$1") # save it in an array for later
    shift # past argument
    ;;
esac
done
set -- "${POSITIONAL[@]}" # restore positional parameters

#ADJUST MAX_SNAPS to prevent off-by-1
MAX_SNAPS=$((MAX_SNAPS+1))

#Tokenize exclude list
declare -A excludes
for token in ${EXCLUDE//,/ }; do
	excludes[$token]=1
done

#iterate over all disks on array
for disk in /mnt/disk*[0-9]* ; do
#examine disk for btrfs-formatting (MOSTLY UNTESTED)
 if is_btrfs_subvolume $disk ; then 
  #check for .snapshots directory prior to generating snapshot
  if [ -d "$disk" ]; then
   if [ ! -d "$disk/.snapshots/" ] ; then
    mkdir -v $disk/.snapshots
   fi
   if [ ! -d "$disk/.snapshots/$date/" ] ; then
    mkdir -v $disk/.snapshots/$date
   fi
  fi
 #iterate over shares present on disk
  for share in ${disk}/* ; do
   #test for exclusion
   if [ ! -n "${excludes[$(basename "$share")]}" ]; then
    #echo "Examining $share on $disk"
    is_btrfs_subvolume "$share"
    if [ ! "$?" -eq 0 ]; then
     #echo "$share is likely not a subvolume"
     mv -v "${share}" "${share}_TEMP"
     btrfs subvolume create "$share"
     cp -avT --reflink=always "${share}_TEMP" "$share"
     rm -vrf "${share}_TEMP"
    fi
    #make new snap
    btrfs subvolume snap -r "${share}" "/mnt/$(basename $disk)/.snapshots/${date}/$(basename "$share")"
   else
    echo "$share is on the exclusion list. Skipping..."
   fi
  done
  #find old snaps
  echo "Found $(find ${disk}/.snapshots/ -maxdepth 1 -mindepth 1 | sort -nr | tail -n +$MAX_SNAPS | wc -l) old snaps"
  for snap in $(find ${disk}/.snapshots/ -maxdepth 1 -mindepth 1 | sort -nr | tail -n +$MAX_SNAPS); do
   for share_snap in ${snap}/*; do
    btrfs subvolume delete "$share_snap"
   done
   rm -rfv "$snap"
  done
 fi
done

 

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Oh, I found the cleanup script needed a similar update with quotes as well when trying to clean up the mess I made while sorting this out lol

 

#!/bin/bash
#description=This script cleans up snapshots.
#arrayStarted=true
#argumentDescription= -i <Comma separated list of shares to purge> or -a to purge all
#argumentDefault=-i share_name_here

shopt -s nullglob
INCLUDE=

POSITIONAL=()
while [[ $# -gt 0 ]]
do
key="$1"

case $key in
    -i|--include)
    INCLUDE="$2"
    shift # past argument
    shift # past value
    ;;
    -a|--all)
    ALL=YES
    shift
    ;;
    *)    # unknown option
    POSITIONAL+=("$1") # save it in an array for later
    shift # past argument
    ;;
esac
done
set -- "${POSITIONAL[@]}" # restore positional parameters

#Tokenize include list
declare -A includes
for token in ${INCLUDE//,/ }; do
        includes[$token]=1
done

#iterate over all disks on array
for disk in /mnt/disk*[0-9]* ; do
 #iterate over each timestamp
 for timestamp in ${disk}/.snapshots/* ; do
  #iterate over each share in the timestamp
  for snap in $timestamp/* ; do
   if [ -n "${includes[$(basename "$snap")]}" ] || [ "$ALL" = "YES" ] ; then
    echo "Purging - $snap"
    btrfs subvolume delete "$snap"
  fi
  #check for empty timestamp
  if [ ! "$(ls -A $timestamp)" ] ; then
   echo "Purging empty directory - $timestamp"
   rmdir $timestamp
  fi
  done
 done
done

Thanks again for this script!

 

Can't wait to see snapshots added to unraid GUI, either officially or in plugin form.

 

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I was inspired by this script so I started out trying to adapt it to work for my UD backup drive but didn't understand how parts of it worked (still new to linux, the exclude and BTRFS check sections made no sense to me).

 

Like normal, it is at your own risk and make sure you have a backup.

 

So I ended up basically re-writing those sections but thus far it seems to work.

 

You will enter the path to the drive(s) you want to snapshot in the UDDRIVE= variables.

 

It will then scan the paths to make sure they are valid and that they are BTRFS drives. It then scans the folders to make sure they are subvolumes and not just normal folders.

 

If the folders are not subvolumes it will let you know that it needs to be put into conversion mode before it can make snapshots. I decided to make this separate as I was not sure of any downsides to automatically doing this and better to error on the safe side.

 

To use conversion mode simply enter "convert" in the argument box and it will convert the folders to subvolumes, it can take some time if you have a lot of files or slow drives. Once the conversion is finished it will exit and you can restart it in normal mode to take a snapshot.

 

The argument is used for the number of snapshot history to keep, 0 will erase all snapshots, good for clearing out space if you deleted a lot of files.

 

My plan is to use it on my weekly and monthly cold backups to give me the ability to get old version of files if it were needed.

 

#!/bin/bash
#description=This script will create a snapshot on unassigned device, perfect for use with a backup drive for example. Simply enter the path drives you wish to snapsshot in the DRIVEX variables. Example: /mnt/disks/backup. Do not include a tailing /. only enter drives that are connected, it will not run if the drive is entered but not detected. The argument is normally used for the number of snapshot history you want to keep. It also includes the ability to convert folders to subvolumes which is needed for snapshots to work. To convert your exsisting folders first make sure you have a backup of your data and then run the script with "convert" in the argument.
#backgroundOnly=
#arrayStarted=
#noParity=
#argumentDescription= Number of snapshots to keep, set to 0 to remove all snapshots (allows you to free up space if you deleted a lot of things). Or put script into Subvolume conversion mode by entering "convert".
#argumentDefault= 12

UDDRIVE1=/mnt/disks/Personal_Data_Backup
UDDRIVE2=
UDDRIVE3=
UDDRIVE4=


DATE=$(TZ=America/Chicago date +@CST-%m.%d.%Y-%H.%M.%S) #standardized datestamp

CONVERSIONPATH=$(echo "$1" | sed -e "s/^convert//")

#check to make sure drive is connected and all folders are converted to subvolumes
for DRIVE in $UDDRIVE1 $UDDRIVE2 $UDDRIVE3 $UDDRIVE4 ; do
	echo Checking that $DRIVE is connected...
	if [ -d "$DRIVE" ] ; then
	   echo "Drive $DRIVE exists"
     echo "Checking that $DRIVE is a BTRFS volume"
	   btrfs subvolume show "$DRIVE"
     if [ $? -eq 0 ] ;  then
        echo
        echo "Drive $DRIVE is a BTRFS volume"
        echo
        echo -----------------------------------------------------------------------------------------
        echo "Now checking that each subfolder is valid BTRFS subvolume"
        echo
        echo
  		  #check that each folder is a BTRFS subvolume, if not warn and suggest convert mode
  			for BTRFSCHECK in $DRIVE/* ; do
  			  btrfs subvolume show "$BTRFSCHECK"
  				if [ $? -eq 0 ] ;  then
  					echo
  					echo "Folder $BTRFSCHECK is BTRFS subvolume, ready for snapshots"
  					echo
  					echo -----------------------------------------------------------------------------------------
  				else
  					echo "Folder $BTRFSCHECK is NOT a subvolume, can not create snapshot, use convert mode to convert it to subvolume"
  						if [ "$1" = "convert" ] ; then
  							echo "-----------------Folder to subvolume conversion mode is Active, DO NOT interrupt, it might take a few minutes-------------------"
                                                        echo
  							mv -v "$BTRFSCHECK" "${BTRFSCHECK}_TEMP"
  							btrfs subvolume create "$BTRFSCHECK"
  							cp -avT --reflink=always "${BTRFSCHECK}_TEMP" "$BTRFSCHECK"
  							rm -vrf "${BTRFSCHECK}_TEMP"
  							btrfs subvolume show "$BTRFSCHECK"
  								if [ $? -eq 0 ] ; then
                                                                   echo
                                                                   echo "Subvolume conversion complete for $BTRFSCHECK. Remove convert from argument now and restart script to take snapshot."
                                                                   echo
  								else
  							           echo Something went wrong with subvolume conversion, see logs. Exiting.
  								   exit 99
  								fi
  						else
  							echo "Folder to subvolume conversion mode not active, Not all folders are subvolumes, can not continue..."
  							echo
  							echo "Enter '"convert"' without quotesin the argument to enable conversion mode"
  							echo "DO NOT interrupt folder to subvolume conversion once started, it can take several minutes if you have a lot of files"
  							echo "Don't run convert mode unless you are sure the drive is a BTRFS drive"
  							exit 99
  						fi
  				fi
  			done
		else
		  echo "Folder $BTRFSCHECK is NOT a subvolume, can not create snapshot, use convert mode to convert it to subvolume"
		  exit 99
		fi
	else
		echo "$DRIVE does not exists. Exiting" ;  exit 99
	fi
done



#if convert mode active, stop script so that max snaps history can be entered in argument
if [ "$1" = "convert" ] ; then
	echo Conversion mode ended, Exiting. If successful Restart script without convert mode to take snapshot
	exit
else
	MAX_SNAPS=$(("$1"+1))
fi


echo Starting Snapshots for all folders on drive,
echo if you get errors make sure that all of the folders have been converted to subvolumes by entering '"convert"' in the argument
echo
for BTRFSDRIVE in $UDDRIVE1 $UDDRIVE2 $UDDRIVE3 $UDDRIVE4 ; do
	if [ -d "$BTRFSDRIVE" ]; then
		if [ ! -d "$BTRFSDRIVE/.snapshots/" ] ; then
      mkdir -v "$BTRFSDRIVE/.snapshots"
		fi
		if [ ! -d "$BTRFSDRIVE/.snapshots/$DATE/" ] ; then
      mkdir -v "$BTRFSDRIVE/.snapshots/$DATE"
		fi
	fi
  for SHARE in  $BTRFSDRIVE/* ; do
    #make new snapshot
    btrfs subvolume snap -r "${SHARE}" "/mnt/disks/$(basename "$BTRFSDRIVE")/.snapshots/${DATE}/$(basename "$SHARE")"
    echo
  done
  #Cleanup old snapshots
  echo "Found $(find ${BTRFSDRIVE}/.snapshots/ -maxdepth 1 -mindepth 1 | sort -nr | tail -n +$MAX_SNAPS | wc -l) old snaps"
  for SNAP in $(find "${BTRFSDRIVE}/.snapshots/" -maxdepth 1 -mindepth 1 | sort -nr | tail -n +$MAX_SNAPS); do
    for SHARE_SNAP in ${SNAP}/*; do
      btrfs subvolume delete "$SHARE_SNAP"
    done
  rm -rfv "$SNAP"
  done
done

echo
echo Finished taking snapshots and cleaning up old snapshots.

 

Edited by TexasUnraid

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this defintelly will need a plugin.. it will be so nice a plugin with a UI with all the snapshots stuff and cronjob configurable.

also this plugin could enable shadow copy smb feature

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On 9/15/2020 at 5:30 AM, segator said:

this defintelly will need a plugin.. it will be so nice a plugin with a UI with all the snapshots stuff and cronjob configurable.

also this plugin could enable shadow copy smb feature

Yep, to be honest I am shocked that a server OS is lacking such basic features as snapshots as a built in feature. Really surprised a plugin does not exists for it either.

Edited by TexasUnraid

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I'm trying to find out documentation about unraid plugin creation, but i can not find too many things.

I have clear idea how to create the page and package the plugin but for exemple if I want to deploy a service that boot just after array start?

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I am sure this exists but no idea where and it is way over my head.

 

I know I found some details on how to make scripts use the unraid notification system purely by chance at some point and it is actually quite simple to do. Got to think there is a thread about the plugin system floating around as well. It could be from a decade ago though.

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Unfortunately so far as i am aware this 

is the best there is. 

 

When last i asked about how to get started creating plugins it was suggested that the best way is to look at the github repos of some of the more prolific plugin writers to see how they constructed their plugins.

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I'm evaluating UnRAID for my new NAS, I modified your script a bit. With it, one can create periodic snapshots with various retention policy (eg. keep hourly backups for a day, daily backups for a week etc). You just need to schedule more copy of the script. I think you can't pass arguments to scheduled script, so I deleted them.

 

(Optional) Add this to your Settings->SMB->SMB Extra. This enables file versioning for smb clients.

vfs objects = shadow_copy2
shadow:sort = desc
shadow:format = _UTC_%Y.%m.%d-%H.%M.%S
shadow:localtime = no
shadow:snapprefix = ^\(monthly\)\{0,1\}\(weekly\)\{0,1\}\(daily\)\{0,1\}\(hourly\)\{0,1\}$
shadow:delimiter = _UTC_

 

Here's the code:

#!/bin/bash
#description=This script implements incremental snapshots on btrfs array drives. Credits @catapultam_habeo
#arrayStarted=true


#If you change the type you'll have to delete the old snapshots manually
#valid values are: hourly, daily, weekly, monthly
SNAPSHOT_TYPE=daily
#How many days should these snapshots last. 
RETENTION_MINUTES=$((7*60*24)) #7 days
#RETENTION_MINUTES=5
#Name of the shares to snapshot, can be comma separated like "medias,valuables"
INCLUDE=valuables
#name of the snapshot folder and delimeter. Do not change.
#https://www.samba.org/samba/docs/current/man-html/vfs_shadow_copy2.8.html
SNAPSHOT_DELIMETER="_UTC_"
SNAPSHOT_FORMAT="$(TZ=UTC date +${SNAPSHOT_TYPE}${SNAPSHOT_DELIMETER}%Y.%m.%d-%H.%M.%S)"


shopt -s nullglob #make empty directories not freak out

is_btrfs_subvolume() {
    local dir=$1
    [ "$(stat -f --format="%T" "$dir")" == "btrfs" ] || return 1
    inode="$(stat --format="%i" "$dir")"
    case "$inode" in
        2|256)
            return 0;;
        *)
            return 1;;
    esac
}

#Tokenize include list
declare -A includes
for token in ${INCLUDE//,/ }; do
	includes[$token]=1
done

echo "RETENTION_MINUTES: ${RETENTION_MINUTES}"

#iterate over all disks on array
for disk in /mnt/disk*[0-9]* ; do
#examine disk for btrfs-formatting (MOSTLY UNTESTED)
 if is_btrfs_subvolume $disk ; then 
 #iterate over shares present on disk
  for share in ${disk}/* ; do
  declare baseShare=$(basename $share)
   #test for exclusion
   if [ ! -n "${includes[$baseShare]}" ]; then
       echo "$share is not in the inclusion list. Skipping..."
   else
     #check for .snapshots directory prior to generating snapshot
	 #only before we make the actual snapshot 
	 #so we don't create empty folders 
	  if [ -d "$disk" ]; then
	   if [ ! -d "$disk/.snapshots/$SNAPSHOT_FORMAT/" ] ; then
		#echo "new"
		mkdir -v -p $disk/.snapshots/$SNAPSHOT_FORMAT
	   fi
	  fi
  
    #echo "Examining $share on $disk"
    is_btrfs_subvolume $share
    if [ ! "$?" -eq 0 ]; then
     echo "$share is likely not a subvolume"
     mv -v ${share} ${share}_TEMP
     btrfs subvolume create $share
     cp -avT --reflink=always ${share}_TEMP $share
     rm -vrf ${share}_TEMP
    fi
    #make new snap
    btrfs subvolume snap -r ${share} $disk/.snapshots/${SNAPSHOT_FORMAT}/$baseShare
	
	#find old snaps
	#echo "Found $(find ${disk}/.snapshots/${SNAPSHOT_TYPE}${SNAPSHOT_DELIMETER}*/${baseShare} -maxdepth 0 -mindepth 0 -type d -mmin +${RETENTION_MINUTES} | wc -l) old snaps"
    for snap in $(find ${disk}/.snapshots/${SNAPSHOT_TYPE}${SNAPSHOT_DELIMETER}*/ -maxdepth 0 -mindepth 0 -type d -mmin +${RETENTION_MINUTES}); do
	   #echo "Deleting: ${snap}${baseShare}"
	   [ -d ${snap}${baseShare} ] && btrfs subvolume delete ${snap}${baseShare}
	   #this will only delete empty directory so it's safe to call
	   #even if there are other backups there
	   rmdir $snap --ignore-fail-on-non-empty
	done
   fi
  done
 fi
done

 

Edited by Tomr
Fixes

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Just wanted to say that I like where you are going with that, it is one of the features I would like to see in a plugin if it is ever made. I have not had time to test it out yet myself though as I am in the process of pre-clearing some drives and don't want to risk having to start that over lol.

 

FYI, You can pass 1 argument to the script, just not more then one as spaces are not allowed in the argument with user scripts.

 

It would be nice to be able to pass a "delete all snapshots" argument of some kind that will remove all snapshots so you can reclaim space if needed. I use this on a fairly regular basis.

 

I suppose it is not possible to change the timezone of the snapshots? It would be handy for it to match the local timezone for hourly snapshots.

 

EDIT: personally I find that an exclude more user friendly as if you ever add a share later it will be included without having to remember to add it manually.

 

With an exclude list, worst case a new share gets snapshotted mistakenly and you have to delete it, reminding you to add it to the exclude list at the same time.

Edited by TexasUnraid

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